ASUS SSD Caching
Although Intel X79 chipset is newer than Z68, it doesn’t support ISRT, the SSD caching feature available on Z68. Instead, ASUS incorporate a Marvell chipset to accomplish a similar task.
ASUS SSD Caching puts commonly accessed data on SSD while it continue storing your data in the larger HDD.
As you are probably aware, ISRT is quite complicated to setup, e.g. must hack the registry to change it back to AHCI mode before you can install the ISRT software. For Marvell based ASUS SSD caching, it is just a one button click and it caching works.
According to tests conducted, ASUS SSD caching is 3 times faster than without cache.
Boot up time is also lowered.
Not only can it work as a cache, it can also function as an extra backup. As it is a hardware solution, it requires almost no CPU cycles. The good news is that there is also no limitation to the SSD capacity unlike ISRT which limits it to 18 to 64GB.